Portal:Physics/Selected article/July 2008



Uranium is a silver-gray metallic chemical element in the actinide series of the periodic table that has the symbol U and atomic number 92. It has 92 protons and electrons, 6 of them valence electrons. Uranium has the highest atomic weight of the naturally occurring elements. It occurs naturally in low concentrations (a few parts per million) in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite. There are many current applications of uranium, including the fissile explosive material used in nuclear weapons, fuel for nuclear power plants, high density bullets, and, prior to the discovery of the harmful effects of its radiation, glass and ceramic dyes, and in luminescent paints...